The field of the invention is cables having both light waveguides and current carrying conductors.
It is well known that it is sometimes desirable to provide cables holding both light waveguides and current carrying conductors. The current carrying conductors may supply power to repeaters to boost the effective light waveguide transmission distance for the cable, or the current carrying conductors may also carry communication messages themselves, providing two different communications media.
More recently, it has been proposed that buried cables holding current carrying conductors may be located by detection of magnetic fields which are generated by electric currents in the current carrying conductors.
It is also known that, particularly in certain areas, light waveguides may be damaged due to melting and crushing forces caused by lightning strikes on the cable. To reduce the possibility of lightning induced damage, dielectric cables may be provided.
Apparently, the prior art does not provide a cable which combines the advantages of a cable having light waveguides in a dielectric environment and the advantage of current carrying conductors.